n a decision that will hearten the pharmaceutical industry, a federal court issued a ruling that may allow drugmakers to defend themselves against product liability lawsuits by citing preemption – which is the notion that FDA approval of a drug supercedes state law claims challenging safety, efficacy or labeling. Preemption, you may recall, was at the heart of a contentious 2009 ruling by the US Supreme Court, which found that a Vermont woman was entitled to sue Wyeth – which is now owned by Pfizer (PFE) – because the drugmaker failed to adequately include safety warnings on one of its medicines. Why? There was no evidence to show the FDA would have rejected a stronger warning if Wyeth had sought to do so. In legal parlance, it was not “impossible” for Wyeth to have attempted to update its label. But the court also left the door open to another scenario that invites a preemption defense. And here it is: If a drugmaker can provide “clear evidence” that the FDA would not have approved a unilateral labeling change to include an updated warning, a drugmaker could argue this demonstrated it was impossible to comply with both FDA requirements and a state law finding for a stronger warning.